Not Applicable.
Not Applicable.
The present invention relates generally to lumbar support devices. More particularly, the present invention relates to lumbar support devices that are capable of changing shape, especially curvature in the lumbar region.
Lumbar support devices have been integrated into seats to change their shape, thereby allowing each occupant to adjust the support provided by the seat. The curvature of these devices is traditionally adjustable so that an occupant can operate the device to push the seat forward towards the occupant""s spinal column in the lumbar region. It is generally known to change the curvature of a lumbar support device using an actuator assembly that moves a support structure, such as a sinusoidal spring element. It is also well known to provide an actuator assembly that is either manually operated, using a handle or knob, or power assisted, using a drive motor and control switches. Increased curvature is usually accomplished by moving the support structure forward into the lumbar region, rotating sections of the support structure into the lumbar region, or bowing the support structure out into the lumbar region.
The present invention is a strap lumbar device having a seat frame, a pair of brackets connected to the seat frame, a spring assembly connected to the pair of brackets in such a manner as to form a center section traversing the seat frame and a pair of cantilevered ends on opposite sides of the center section, and an actuator assembly operatively connecting the cantilevered ends. The pair of brackets respectively provide a pair of fulcrums about which the cantilevered ends can rotate.
In the preferred embodiment, the spring assembly has two integrally-formed, sinusoidal spring elements attached by a connector, and the center section of the spring assembly has a recessed portion. In other embodiments of the invention, a single sinusoidal spring has only one cantilevered end that rotates about a bracket, and a leaf spring is cantilevered about a pair of coil springs. The lumbar support device can be oriented horizontally or vertically in the seat frame, and the orientation of the cantilevered ends can be reversed.
In operation, the fulcrums allow the cantilevered ends to function as levers. The actuator assembly moves the levers which rotate about the fulcrums and bow the center section. The fulcrums are located between the distal end of the levers and the center section of the spring to stop the lever from sliding in the bracket and force the lever to rotate about the bracket.
It is a purpose of the present invention to provide a lumbar support device that is simple and affordable to manufacture.
It is a further purpose of the present invention to provide a mechanically simplified lumbar support device that has a thin profile when flat.
Further advantages of the present invention will be apparent from the description below with reference to the accompanying drawings in which like numbers indicate like elements.